Recently I have done a mini CNC router using salvaged parts of two old printers, a DVD-RW and some parts of old computer case. With special thanks to lovely Instructables which I got the main idea from and the Diylilcnc that inspired me for mechanical structure.
I’ve used the printer spindle and ink container as main moving part of X-axis. As you may know, the inkjet printers (or kinds that I’ve seen ever) use DC Motor for moving and a jog wheel or gradient band with a phototransistor (or something like that) together. Therefore, I changed the DC motor with a stepper motor to handle the speed control and reverse movement.
For the Y-axis, I used four ball-bearings fixed in the middle track of side-rails of a computer case. I hadn’t any proper gearbox, so I had to connect the belts, directly to the motors. It made me the easier mechanical structure, but in the way of losing some precise.
Finally, for the Z-axis, I’ve used the optic moving DC motor of a DVD-RW. The entire result is satisfactory.